General sportbike windscreen design, LeMans IV specific

[brider]

There is a recent post where the question is how to re-direct the windblast off the LM IV windscreen to the particular rider's chest, rather than his neck:

http://wildguzzi.com/forum/index.php?topic=96580.0

I'm new to riding a LM IV, so riding in to work today I tested where the windblast coming off the top of the stock windscreen was flowing with respect to my helmet, by feeling with my left hand over the windscreen @ 70-80 mph (that bike seems like it has a sweet spot @ 80).

The blast feels like it's directed exactly at my faceshield. Is this normal?

I do not experience "buffeting" like I have before behind a troublesome barn-door windshield on my Cal II where your vision gets blurry (fixed that problem), and I can turn my head no problem, as if the flow hitting my helmet is smooth, and my helmet is behaving like a spherical shape.

Do you guys who ride sportbike variations of the LM IV take steps to modify the windscreen, or your riding position, to get the windblast OVER your helmet? In the link above, the attempts to get the blast lower on the chest, in my case, would still leave my head in open airflow, but I'm wondering if the helmet roar would be reduced from having the direct blast hitting my face.

As it is now, I was thinking of adopting the practice of earplugs, just wondering if I should experiment with different windscreens.

[Groover]

Earplugs in the helmet is probably a good start. I've been following these LM4/5 windscreen threads, never realized these were an issue until lately. Seems cutting the ducktail off the windscreen would make thinks worst by bringing the airstream down instead of over the head, though sounds like that is the solution for some? Have you tried playing around (maybe temporarily remove) the side/tank spoilers and then test it again at that same speed? Something is causing the airstream to be pulled down in that spot too soon instead of behind the person. We need an aerodynamics guru on this one. I bet some side flow holes or slight bump-out or in on the fairing or something along those lines would redirect that airstream away from wrapping in front of the head, but that's a lot of windshields and fairings to cut and test aimlessly That low pressure zone needs increased maybe?





Edit: Maybe try a different helmet?: https://tinyurl.com/y7e8f9zc

Edit 2: This is what I was thinking. Slits or holes on the bottom side of the Lm4 fairing. Of course, a wind tunnel would be a great tool for this one 

[Chuck in Indiana]

Cutting off the lip made all the difference on the AeroLario.

As it is now, I was thinking of adopting the practice of earplugs, just wondering if I should experiment with different windscreens.

No matter what you do.. adopt the earplug practice. Trust me on this.